+1  A: 
 @media print { 
    .footer {display: block;}
 }
 @media screen {
    .footer {display: none;}
 }

anything of class=footer will appear only in print. It's up to you to locate it at the bottom of the page.

SF.
+2  A: 

You can specify a CSS stylesheet to be used for a media type of print and include that in your webpage. In that stylesheet set appropriate options to "turn on" the footer element that you want whilst in the "screen" version that element might not be visible.

<link rel="stylesheet" type="text/css" media="print" href="style.css">
Trevor Tippins
+1 - The media='Print' is useful.
Mark Brittingham